Influence of α morphology and volume fraction on the stress-induced martensitic transformation in Ti-10V-2Fe-3Al

This paper reports an investigation into the influence of alpha morphology and volume fraction on the critical stress levels for the stress-induced martensitic transformation in Ti-10V-2Fe-3Al. Control of the stress-induced martensite transformation offers a new route to the optimization of the load bearing capabilities of titanium alloys. Various heat treatments in alpha + beta and beta + (alpha + beta) conditions were imposed to study their effect on both microstructure and mechanical properties. The results show that in samples with globular alpha, the beta matrix stability is the main factor controlling the stress-induced martensitic transformation. For samples with acicular alpha, the grain size (i.e. the size of the retained beta domain), which governs the mean length and the width of martensitic plates, also plays an important role in such transformations. The linear combination of both effects provides a good prediction of the stress-induced martensite formation stress as a function of the volume fraction and morphology of the alpha phase. (C) 2011 Elsevier B.V. All rights reserved.